Alco C-855 R-T-R Build – Part 6 – Trucks & Pilots

This week’s post will be a continuation of my step-by-step build of an N Scale A-B-A ready-to-run set of Alco C-855 locomotives.  And this post will be concentrating on the trucks and pilots.  You can find part one of the build here.

Now the chassis are all ready, stretched, notched and DCC fitted as shown below, we need to turn to the cosmetic parts.

The three chassis supplied for this build came from locomotives painted in different railroad liveries and consequently the trucks and pilots are all different colors.  And the one at the bottom of the image below has been weathered.

The C-855 has silver trucks and UP Harbour Mist Gray pilots as you can see in the photo below.  (Taken from American-rails.com).

The truck assembly is fairly straight forward.  The two screws on the front truck hold both trucks to the locomotive.

The front truck side frame and rear truck then lift off leaving the wheels behind.

Inside the rear truck is a metal weight which holds the wheels in place.

The weight is removed by taking out the last screw.  This also separates the two trucks.

The wheels are fixed between the truck side frames and can easily be removed by gently spreading the side frames outwards until the wheels pop out.

Next we have the pilots. The front pilot is a plastic molded section which is clipped over the two metal truck sections.  The truck is in two sections to electrically isolate each side.

On the top are two tabs which can be pushed apart and the pilot drops down.  This also releases the coupling and spring so make sure it doesn’t fly off.

The rear pilot has a similar plastic molded section but this time it fits on the top of the truck sections.  There is an extra clip which fits under the pilot to hold in the coupling and spring.  In the picture below I have removed the clip.

The coupling, spring and spring box is then removed as shown below.

Lastly the rear pilot can be slid off the truck sections.

The two sections as shown below are ready for painting as are the four truck side frames.

The painting will be covered in a later post as will the re-assembly of the trucks where I will cover changing couplings.

Alco C-855 R-T-R Build – Part 3.5 – Chassis Prep Extra

This week I have an extra post to slip into my step-by-step build of an N Scale A-B-A Ready-To-Run set of Alco C-855 locomotives.  Back in July I posted part 3 which covered the chassis preparation procedure, you can find it here.  However I missed something so in this post I’ll cover what it was and how to do it.  My apologies to anybody who has been following this build along with me.  I will update part 3 which will make this post redundant but for now here it is.

You may have noticed I regularly recommend test fitting things as you go and I should take my own advice.  The chassis below has been prepped to fit into a C-855 A unit and at the cab end you can see how the top chassis section has been notched to fit into the narrow nose.

But the lower section doesn’t fit all the way in and a test fit before I assembled the chassis would have told me that.  In the picture below I’ve removed the lower chassis section and placed it into the shell.  As you can see the inside corners of the nose clip the shell.

However this is easily fixed by cutting two notches in the chassis section as marked below.  Each notch is 3.5mm (0.1377“) wide by 2mm (0.0787“) deep leaving a nose of about 6mm (0.2362″) wide.

I cut these out using my Dremel tool and cutting disc.

The bottom chassis section now fits into the shell.

This extra notching is not required for the C-855B chassis as it doesn’t have a nose.  Next, as I have disassembled and resembled the chassis, I’ll test them for running smoothness and any binding in the drive shafts. Then it’s on to the shells which will be in a later post.

Alco C-855 R-T-R Build – Part 4 – Chassis Assembly

This week’s post will be a continuation of my step-by-step build of an N Scale A-B-A Ready-To-Run set of Alco C-855 locomotives.  And this post will be concentrating on assembling the chassis.  You can find part one of the build here.

Now the chassis sections have been extended it’s time to reassemble all the parts.  And for this build I’m also going to upgrade all the motors to newer Kato drives.  In the picture below you can see all the original parts plus the new Kato motor in the top left-hand side.

For this post I’m going to assemble the second chassis which you may remember from last week is for the B unit but the process is exactly the same for all three locos.  To start with I add the black plastic isolators into the pockets on the underside of the lower chassis section followed by the metal truck fixing.  Both are held in place by a countersunk screw, the shortest ones, which only pass through the lower chassis section.

Next, and this in an important one not to miss, the first new 3D printed part needs to be added.  It’s the small square screw fixing which holds on the fuel tank.  In the original the lower chassis has a threaded hole to receive the screw but as this section has been replaced by the stainless steel chassis extender a new fixing is required.  Threading the hole would require more work and it’s much easier to drop in this plastic part.

The square part simply presses into the square hole.

It will stay in place by friction and once the motor is fitted it can’t fall out.

The motor sits in a plastic cradle; this is to isolate it from the metal chassis.

The cradle has a peg on the bottom which fits into the hole in the chassis to ensure it’s in the right way around.

Next comes the motor.  Although I’ll cover this here I’ve written about this procedure before in a bit more depth which you can find here.  The new Kato motor doesn’t come with any gears on the drive shafts so the original ones will need to be removed from the old motor.

This is actually fairly easy to do.  I use a pair of needle nose tweezers, simply grip the shaft behind the gear and push it off.  Just don’t do it too fast or the gear will ping off behind the work bench!

To fit the gears to the new motor simply press them on with your fingers.  They want to go on so far that the shaft pokes out the other side but make sure the gears are not tight to the motor body and the motor can spin freely.

The next 3D printed parts are the drive shaft extenders.  These are toothed parts which fit inside the existing cup gears making them longer.

I used to glue these in but as my fellow modeller Mike Musick pointed out, they work better when left free with a bit of movement.  You can read Mike’s views on this here.

Also, as you may remember from last week’s post, Con Cor have over the years made a few changes to their chassis and one of those changes was to this cup gear.  The very first design had a different number of teeth in the cup.  This means the extender won’t fit.  But don’t panic, firstly these early chassis are now getting rather rare but if you are using one for you C-855 build you can get drive shaft extenders which will fit here.

The motor is now ready to be added into the chassis.  But first it’s very important to make sure the new drive shafts spin freely without any rubbing on the chassis. Across all the Con Cor chassis I’ve converted I’ve noticed that the drive shaft length varies; I have no idea why.  I’ve supplied the drive shaft extender for the more common shorter lengths I’ve come across.  This does mean that if you have longer ones the drive shaft will now bind against the chassis extender.  To overcome this pop the drive shaft back out and file down the 3D printed part on the cup side.  Running the part up and down a file will do this.  But be sure to make the reduction even.  I would also recommend doing a bit at a time and test fitting as you go as you don’t want to make them too short.  If you do you can get more here.  Once everything is good this would be a good time to add a tiny amount of light oil to each bearing, just a drop.

There may also be one more issue to resolve if you’re using the latest Rail Barron version of the chassis.  Con Cor updated the motor casing and added the curved notches you can see in the picture below.  And therefore added some material into the motor cradle so it’s a nice tight fit.  But this means the Kato motor won’t fit!  It fits fine in all the others.

These extra plastic parts need to be removed to get the new Kato motor in and I find the best way to do it is with a with a small burr bit in a Dremmel style tool.

All four corners will need to be removed to allow the new motor to fit.

Also, and this apples to all the cradles, a shim needs to be added to the base of the cradle as the new Kato motor is slightly shorter than the Con Cor one.  Before you glue the shim in a test fit is required because if it’s too thick it will create uplift on the cup gears which will be noisy and wear out the motor.

The motor fits in to the cradle with the motor contacts at the end with the larger hole.

You’ll need to lift the drive shafts in order to fit the motor in.

Once fitted and you’re happy that everything spins freely, and the motor turns both drive shafts, it’s time to add the rest of the chassis.  There are two plastic separators which also hold down the drive shafts, these get fitted next.

Then the top section of the chassis can be fitted and the other screws fitted between the top section and the metal truck fixing. The longest screws with a plastic insulator are used on the right hand side.  The medium screws are used on the left without insulators.

With the trucks installed the extended chassis should look like this.

At this point, using wires from a DC controller, I do a basic test to make sure everything runs well.  If it’s noisy, won’t run, or sounds like it’s struggling, STOP,  there are a few things to check.

  • Can you easily turn the motor with your finger?
  • Are the drive shafts seated properly?
  • Check the drive shafts are not too long and binding on the chassis.
  • Check the gears on the motor have been pushed on far enough but not too far.
  • Is the shim under the motor too thick forcing the gears up into the cup gears?
  • Are the gear towers in the trucks jammed?

Hopefully everything runs okay with all the checks done and any issues corrected.

The next step is to wire up the chassis, I will be doing this for DCC but I’ll cover DC as well and it will all be in the next post on this project.

Alco C-855 R-T-R Build – Part 2 – Grab Irons

This week I’ll be continuing my step-by-step build of an N Scale A-B-A Ready-To-Run set of Alco C-855 locomotives.  And this post will be about the first details to be applied to the shells; the grab irons.  You can find part one of the build here.

The grab irons or hand rails are small parts but form an important detail.  For these models I’ve made them from etched brass rather than a part of the 3D printed shell.  I could make them a part of the shell but they would be extremely fragile and probably couldn’t withstand being handled without breaking.  The other option’s to make them a solid piece of the shell but I find that makes them look too bulky.

The grab irons are located in the etched brass frets as shown below.  There are two sets for the A units and one for the B unit.

Each 3D printed shell already has the holes to locate all of the grab irons, and other parts.  Below you can see the cab of the A unit with the various holes.

And the rear also has holes for the four grab irons which create the ladder to the top of the locomotive.  Both ends of the B unit are the same as the rear of the A.

There are two types of grab iron.  Straight and folded down and in the A unit fret there are eight of each, although you only need 7 of the straight ones.

The straight ones have half etched sections where they are connected to the main fret to allow them to be easily cut out with a sharp knife.

One thing I strongly recommend is to test fit each grab iron.  If the hole is clogged or the grab iron is slightly bent the wrong way and you attempt to glue it right in, one leg will stick and the other will bend and you’ll be left with a wonky grab iron.  Each grab iron fits into a pair of holes which are either all the way through the shell or just the right length. So if you’ve cut them out too close to the fret and they are too long they may stick out too far.  This is another good reason to do a test fit.

The folded down version also has half etched sections on the rear just after the corner.   This allows the grab iron to easily be folded down in the right place.

I find by using a pair of wide tweezers I can hold both the legs and simply bend the fold down section into place with my finger.  When I tried it the other way round it was hard to get both legs in the right place.

I tend to get all the grab irons ready together, but I keep the two types separated.

To secure them in place I use superglue.  This is a great choice, not only because it sets very quickly but it is a type of acrylic and so are the 3D printed shells so there’s no danger of a chemical reaction damaging the shell.  I wouldn’t recommend trying to apply superglue directly to the shell; that normally ends in a sticky mess.  The best way is to pour some onto an old box lid or something similar, then gently dip the tips of the grab iron into the superglue just before you place it into the holes.  After you have test fitted it of course.

The straight grab irons fit in the A unit cab in six locations; I know there are only five shown below, I forgot one but it will appear shortly.  There are two in the roof above the number boards, two in the face of the cab above the outer windows, one in the side of the nose, above the step area, and finally, although not shown yet, one on the top of the nose.

The seventh fits in the top of the shell at the rear. The last one is simply a spare.

Three of the drop down grab irons fit into the side of the nose under the straight one.  These are the only three which don’t fit into two holes; the rear leg of each grab iron does but the front simply glues onto the front of the nose.  There is small sections of the 3D printed shell which stick out to locate the grab irons which sit on top of them. There is a fourth fold down grab iron under one of the windows.

When complete the fronts look like this. The B unit front is the same as the rear.

And the rears look like this.

The B unit fret has eight fold down grab irons and two straight ones.

So why have I only fixed the grab irons and not the rest of the etched brass parts?  Well these are the most delicate to do and also these need to blend in when the locomotives are painted. All the rest will be fixed after painting as they either fixed to several different parts or will make painting the shell harder to do if fitted first.

These shells will now go in for painting and while that’s happening I’ll turn my attention to the chassis which I’ll share with you next week.

Alco C-855 R-T-R Build – Part 1 – All the Parts

As promised in an earlier post I’m going to share with you the process of building an N Scale A-B-A Ready-To-Run set of Alco C-855 locomotives.  And this post is the first one covering all the parts.

I released the C-855 kit back in the beginning of 2016 and have made a few since then but as a fellow modeller has asked me to make a complete set for him, two A units and a B, I decided to document the whole thing to help others, as this build is a bit more tricky than normal.

So where to start?

I guess the best place is to show you all the parts you will need.  This will include 3D printed parts, donor parts, new parts and etched parts.

The 3D printed parts, as shown below, are all supplied by Shapeways in their Fine Detail Plastic material; originally called Frosted Detail Plastic.  This material is available in two quality levels; smooth and smoothest. The difference is the layer thickness, Smooth being 29 microns and Smoothest being 16 microns.  The Smoothest option takes longer to print and is therefore more expensive.  Since releasing these models Shapeways have also introduced their option to set the orientation of prints so the best detail can be achieved in the areas where you want it.  However, this also comes at a higher cost and as these engines are so big it did make a considerable difference to the price.  So I offer them in orientated and unorientated versions.  To find out more please see the C-855 page here and the C-855B page here.

The parts 3D printed in Fine Detail Plastic, starting from the top, are:

  • C-855 Locomotive Shell
  • C-855B Locomotive Shell
  • C-855 Locomotive Shell
  • 3 Fuel Tanks & 6 Drive Shaft Extenders
  • 18 Sand Boxes
  • 4 Special Sand Boxes, 4 Crew, 3 Sets Of Horns, 4 More Sand Boxes & 3 Fuel Tank Mounts

Since arriving from Shapeways all the parts above have simply been rinsed under warm water, soaked for twenty-four hours in Goo Gone, rinsed again in warm water, left to dry for forty-eight hours and finally run over lightly with a brush in a Dremel style tool as shown below.

I use this tool as any residue left over from the print process turns to powder after contact with the Goo Gone; once dry the brush simply knocks it off.

The next set of parts is the chassis.  For these locomotives, if you want them to be powered, you will need to get a donor chassis from a Con Cor U50 or turbine.  This is the only thing currently available which is even close to the C-855 chassis.  However it is too short and needs to be lengthened.  I will cover that later.

The parts for the chassis, starting from the top, are:

  • 3 Con Cor U50/Turbine Donor Chassis
  • 3 Sets of 3D Printed Stainless Steel Chassis Extenders
  • 3 New Kato Motors

The chassis extenders are also 3D printed by Shapeways and can also be found on the C-855 page here and the C-855B page here.

The new motors are not necessary for the build but the old Con Cor motor, although reliable and strong, is rather noisy by modern standards and this particular Kato motor works well as a replacement.  You can read a post about swapping them here with and an update here.

The last set of parts, well almost, is the etched brass parts as shown below. These are etched in 12 thou brass to give strength to the long parts.

Each etched set of C-855 Additions, as shown below contains:

  • 7 Handrails
  • 16 Grab Irons
  • 4 Ladders
  • 3 Walkway Platforms
  • 2 Sun Visors
  • 4 Windscreen Wipers
  • 4 MU (Multiple Unit) Hoses
  • 2 Miscellaneous Pipe Sections

The etched set of C-855B Additions, as shown below contains:

  • 8 Handrails
  • 10 Grab Irons
  • 4 Ladders
  • 3 Walkway Platforms
  • 4 MU (Multiple Unit) Hoses
  • 2 Miscellaneous pipe sections

The only other thing I’ll need for this build is three DCC decoders, LEDs for headlights and relevant wire but I’ll come to that in a later post.  I’ll also start working on the preparation of the parts leading up to the assembling of the locomotives.

This week I’ll finish off by saying I, along with my club members and club layout ‘Solent Summit’, will be at the Great Central Railways model railway exhibition from the 15th to the 17th June 2018.  You can find our more here.  And if you time it right you’ll see an A-B-A set of C-855s running on the layout.

3D Print Orientation and What To Do When It’s Wrong

As promised in last week’s post this week I’m going to share with you how to identify if your 3D printed model has been printed correctly.

So what do I mean by correctly printed? Back in October of 2017, in a post which you can find here, I shared with you the new feature from Shapeways which allows the orientation of the print to be set.  This means parts such as a locomotive shell can be printed with the roof on top ensuring the smoothest detail, rather than upside down like a bath tub.

However sometimes, even though the print orientation has been set, some models slip through the printer’s checks and get printed in a cost-saving way; this normally means upside-down.  But how can you tell?  Well, there are a few tell-tale signs which are caused by the print process which give away the orientation of the print.  These signs can be seen when the model is first delivered but given the transparent nature of the material it is fairly hard to spot and nearly impossible to photograph.

So the first thing I always do with any model is soak them in Goo Gone for 24 hours, which makes them opaque, rinse them under warm water and leave to dry for another 24 hours.  Below you can see a set of Alco C-855 shells which have been through this process.  These shells were ordered with the print orientation set so they printed the right way up and at first glance they look good.

But a closer inspection reveals they have been printed upside-down.

The first clue is the direction of the print shadow. The print shadow is the area under a section which sticks out.  In order to print this section support material is required to literally support it. However, where this support material comes into contact with the actual model it leaves a slighty rougher finish which is called the print shadow.  For example, in the image below you can see the print shadow running up from the bolt detail around the base, which means the model was printed upside-down. As the bolt detail protrudes out from the base a bit of support material was required under it. Also looking at the doors and vents on the side of the body you can see these were also covered in support material in order to print the base which also projects out further.

This effect is repeated on the rear as shown below.

The second clue is the inside of the model.  In the picture below you can see all the detail is crisp and smooth.  This is because it hasn’t come into any contact with support material.  This is the best finish on the model and sadly it’s the one location where it’s not needed.

The third clue is the actual top of the model.  It should be smooth, like the inside, but as you can see it’s rougher and ‘furry’ with support material residue which has turned into powder because of the Goo Gone.  The whole of the top of the model has been submerged in support material, because the model was printed upside-down instead of the right way up as requested in the orientation setting.

Now, these shells are not bad and the powder residue can easily be removed with a soft brush in a Dremel style tool, or by hand with a brush, leaving you with a good model.  But the surfaces which should have been on top will never be as good as the finish on the inside and areas such as the doors and vents will also be a bit rougher.

So what should it look like? Below is another set of Alco C-855 shells. You can see that after the cleaning process the finish on the outside is not all the same colour. This is because a lot of the surface hasn’t come into contact with support material, as we wanted.

There is still a print shadow effect but this time it’s running down the model and not up.

The doors and vents still have some print shadow but only in a few areas such as the recess for door hinges etc.

The inside of the shell is rougher and covered in print shadow, as we would expect as it was full of support material.

The top is smooth and very well detailed which will show up when the shells are painted.  In the pictures they look rough or lined but this is simply where the Goo Gone has not affected any support material residue and the surface is still a bit transparent.

Hopefully this will help you identify if a model has been printed in the correct orientation or not.  But what should you do if yours arrives and you think it was printed the wrong way up?

Firstly check to make sure the model was designed to have the orientation set. I can’t speak for other designs but my models will state this in the description if it has been set and I can always confirm if you want to contact me and check.  As for the Alco C-855 shells you need to purchase the Deluxe version as it’s not set on the standard.

Secondly, take some pictures of the incorrect model showing things like the print shadow running the wrong way.  Then send an email to Shapeways at service@shapeways.com.  Include your order number, photos and let them know the model you received has not been printed in the correct orientation. Please note: this must be done within ten days of receiving the model.  Their customer service team are quick to respond and will organize a re-print of the model if indeed it was printed wrongly. But again, you only have ten days from the time you receive your print.

As I said before any excess powder will need to be cleaned off and you will find the detail is good underneath it.  You also need to clean this off otherwise any paint applied will flake off as the powder is loose.

You may also be wondering what I’m doing with so many Alco C-855 shells?  These are for a fellow modeller and I’m making a fully powered ready to run A-B-A set for them.  And I intend to share the whole build process with you in a set of posts which should be starting very soon.